In a first attempt at monitoring ground level ozone in Aspen, the City of Aspen found Aspen’s ozone levels for the month of January well below the national standard.

The Environmental Health Department began monitoring for ground level ozone on December 30, 2009.

“Staff decided to expand Aspen’s air quality monitoring to include ozone when they heard that the U.S. Forest Service had recorded the highest level of ozone for the Western Slope on top of Aspen Mountain in the summer of 2007 at a level of 79 ppb (8-hour average),” said Jannette Whitcomb, environmental health program coordinator for the City of Aspen.

The concentration was above the Environmental Protection Agency’s (EPA) acceptable level for the gas of 75 ppb (8-hour average).

At ground level, ozone is detrimental to human health. It can trigger chest pain, coughing and congestion, and can worsen asthma, bronchitis and emphysema.

“Aspen’s active population is particularly susceptible to its effects as are Pitkin County’s high percentage of people with asthma,” said Lee Cassin, environmental health director.

The air pollutant also damages crops, trees and other vegetation. In Aspen, ozone is likely a result of oil and gas drilling in the region and motor vehicle exhaust and gasoline vapors.

Located near the intersection of Highway 82 and Cemetery Lane, the City’s ozone monitor will help determine if levels in the Aspen area are below EPA’s standard of 75 ppb, an analysis that will require three years of data.

In the near term, if levels approach the EPA standard, staff will take action by cross referencing weather, traffic and oil and gas data in light of the new monitor’s results. This information will allow officials to determine what actions, if any, are needed to reduce ozone levels.

“The monitoring system is designed to provide real-time ozone readings on an hourly basis,” Whitcomb said. “But it’s not surprising that Aspen was within levels in January. That is the case for most cities during the winter. Summer is the major ozone season given how ground level ozone is formed.”